Stepper Motor Vehicle Axle Mount - Arduino basic kit.

I want to make a basic R/C car from the basic Arduino starter kit.

Step one is mounting the included stepper motor to an axle for the rear drive wheels.

This is the minimalist mount for that - I am imagining that I'll fix it to a chassis using the two bolts already used in the project.

I'd like to not use any additional parts, but for now it needs an axle (mine seems to be 1.88mm diameter, I guess its supposed to be 2mm) and the two bolts are m4's

I plan to do a mount for the servo t